Nelmastobart in Combination With Tas-102 and Bevacizumab in Recurrent/Metastatic Colorectal Cancer

NCT07656038 | Not Yet Recruiting Phase 1

• 1 other identifier: STCUBE-003CN-01
• Study Type: interventional
• Target: 45
• Locations: 0 countries
• Sites: N/A

Brief Summary

Nelmastobart（hSTC810） is a novel humanized monoclonal antibody that fuses on IgG4 and targets a novel immune checkpoint protein, BTN1A1+.This is an phase Ib bridging trial conducted in China to assess the safety, tolerability, and pharmacokinetic characteristics of Nelmastobart in combined with TAS-102 and Bevacizumab in Chinese participants with mCRC, and to verify that the safety results align with those from the Korean STCUBE-003 phase Ib trial. The phase Ib trial will also provide supportive data for conducting a randomized, double-blind, controlled Phase II study in China.

Conditions

Colonrectal Cancer (CRC)

Outcome Measures

Primary Outcomes (3)

• Incidence of DLT

  Definition of DLT: The severity of AEs observed during the trial was determined and recorded according to the NCI CTCAE v6.0 grading criteria. The DLT observation period spanned the first treatment cycle (i.e., from C1D1, the first administration, to C1D28).According to the definition of DLT, "drug-related" is defined as follows: an AE is considered to be related to the investigational product if, in the opinion of the investigator, the relationship is "definitely related," "likely related," or "possibly related."

  up to 6 months

• Permanent discontinuation of IP due to adverse drug reactions (ADRs)

  The incidence and rate of permanent discontinuation of IP due to adverse drug reactions (ADRs)

  up to 6 months

• AEs(Adverse Events)

  Status of AEs will be presented with frequency, percentage and its 95% CI. AEs will be classified by SOC and PT of MedDRA (latest version) and presented with frequency, percentage and its 95% CI.

  up to 6 months

Secondary Outcomes (5)

• Maximum plasma concentration (Cmax)

  up to 6 months

• Objective response rate (ORR)

  up to 6 months

• Immunogenicity indicators:

  up to 6 months

• Tmax(Time to Maximum Plasma Concentration)

  up to 6 months

• ORR assessed by researchers

  up to 6 months

Other Outcomes (3)

• Exploratory evaluation indicators.

  up to 6 months

• ORR between different levels of BTN1A1

  up to 2 years

• Efficacy vs. BTN1A1

  up to 2 years

Study Arms (1)

Nelmastobart in combination with TAS-102 and Bevacizumab for recurrent/metastatic CRC

EXPERIMENTAL

Drug: Nelmastobart in combination with TAS-102 and Bevacizumab

Interventions

Nelmastobart in combination with TAS-102 and Bevacizumab DRUG

1. Drug name: Nelmastobart. Specifications: 400 mg/8 ml. Formulation: Sterile concentrated solution for injection. Batch number: XXX. Manufactured and supplied by Samsung Biologics Co., Ltd. (SBL), on behalf of STCube, Inc. 2. Drug name: Qufluorodeoxyuridine/tipiracil. Specifications: 15mg, 20mg. Formulation: film-coated tablet. Batch number: XXX. Produced and supplied by Taiho Pharmaceutical Co., Ltd. 3. Drug name: Bevacizumab. Specifications: 100 mg, 400 mg. Formulation: concentrated solution for injection. Batch number: XXX. Produced and supplied by XXX Company. Experimental: Cohort (Phase 1b) Nelmastobart 800 mg + Tas102 35 mg/m² + Bevacizumab 5 mg/kg (Starting Dose)

Nelmastobart in combination with TAS-102 and Bevacizumab for recurrent/metastatic CRC

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults ≥18 years old and of any gender when signing the informed consent form.
• Participants with metastatic/recurrent colorectal cancer confirmed by histopathology/cytology who have not responded to or are unable to receive standard anti-cancer therapy based on oxaliplatin and irinotecan. Participants who undergo curative surgery for colorectal cancer and receive adjuvant anti-cancer therapy will be considered to have received their first palliative anti-cancer therapy if their disease recurs during or within 6 months after completion of the adjuvant anti-cancer treatment.
• According to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, there must be at least one measurable or assessable lesion present.
• Participants with ECOG performance status 0-1
• Participants with adequate bone marrow and body organ functions
• Absolute neutrophil count (ANC) ≥ 2.0 x 109/L
• Hemoglobin count (Hgb) ≥ 9.0 g/dL
• Platelet count ≥ 100 x 109/L
• Serum creatinine ≤ ULN x 1.5 or serum creatinine clearance \> 30mL/min
• Total bilirubin ≤ 1.5 x ULN (Participants with biliary obstruction may be enrolled if they meet the criterion after adequate biliary drainage.)
• AST and ALT ≤ 3 x ULN in the absence of liver metastasis;
• or AST and ALT ≤ 5 x ULN in the presence of liver metastasis
• Confirm that participants with adequate cardiac function at the screening visit QTc calculated using the Fredericia formula ≤ 480 msec (Those with QTc \>480 msec may be enrolled if the mean of 3 consecutive QTc measurements is \<480 msec.).
• A negative serum β-HCG test within 14 days prior to IP dosing for women of childbearing potential
• Participants who agree, and are able to use during the study medically reliable methods of contraception as follows:

You may not qualify if:

• Participants who have hypersensitivity to the active ingredient of IP or any of its components (excipients)
• Participants who had cytotoxic chemotherapy within 14 days prior to randomization; treatment with IP in another clinical trial with the elapse of ≤2 weeks from the last dose of that IP or ≤5 folds the half-life of that IP; or treatment with monoclonal antibody therapy within the past 4 weeks
• Uncontrolled serious infection
• Confirmed PD during treatment with trifluridine/tipiracil for palliative care or confirmed recurrence within 6 months after the end of such treatment
• Participants requiring high-dose steroids (\>10 mg/day prednisone or equivalent) or other immunosuppressants However, these participants may be enrolled in the following cases.
• Short-term (\<7 days) use of systemic corticosteroids that are considered standard of care will be allowed.
• Participants requiring intermittent use of bronchodilators, inhalant steroids, or local steroid injections will be allowed.
• Replacement therapy (e.g., thyroxine, insulin, physiological corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered as a type of systemic treatment and will be allowed.
• Pregnant or lactating women
• Participants with a history of autoimmune disease requiring systemic treatment (i.e., use of disease modifying therapy, corticosteroids, or immunosuppressants) within 2 years prior to the screening visit (However, enrollment will be possible for subjects with vitiligo, psoriasis not requiring systemic treatment, type 1 diabetes mellitus, hypothyroidism stably managed with hormone replacement therapy, Sjogren's syndrome, or resolved pediatric asthma/atopy.)
• Participants with active central nervous system lesions (radiologically unstable or symptomatic brain lesions). With the exception of patients with meningeal metastasis, individuals who had radiotherapy or surgical treatment may be enrolled if there is evidence that the patient's condition is maintained without steroid therapy and that the disease of the brain lesion has not progressed for ≥4 weeks.
• Participants with a documented history of cerebrovascular events (stroke or transient ischemic attack), unstable angina pectoris, myocardial infarction, or cardiac symptoms consistent with New York Heart Association (NYHA) Class IV within 6 months prior to the screening visit
• Participants with hypertensive encephalopathy or hypertension that is not adequately controlled with antihypertensives
• Participants with a history of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, or idiopathic pneumonia; or with active pneumonia based on screening chest X-rays
• Participants who received allogeneic stem cell or solid organ transplants

Sponsors & Collaborators

• STCube, Inc.: lead

MeSH Terms

Interventions

trifluridine tipiracil drug combination; Bevacizumab

Intervention Hierarchy (Ancestors)

Antibodies, Monoclonal, Humanized; Antibodies, Monoclonal; Antibodies; Immunoglobulins; Immunoproteins; Blood Proteins; Proteins; Amino Acids, Peptides, and Proteins; Serum Globulins; Globulins

Central Study Contacts

Zhang Jian, M.D

CONTACT

0086-13911127863; zhjian940105@163.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 27, 2026
• First Posted: June 18, 2026
• Study Start: June 30, 2026
• Primary Completion (Estimated): July 31, 2028
• Study Completion (Estimated): July 31, 2028
• Last Updated: June 18, 2026

Record last verified: 2026-05